package csci6450.chickenFriedFS.nuggetCore;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 *
 * @author jacobschoen
 */
public class NuggetUtilities {

    public static byte[] getBytesFromFile(File file) throws IOException {
        InputStream is = new FileInputStream(file);

        // Get the size of the file
        long length = file.length();

        // You cannot create an array using a long type.
        // It needs to be an int type.
        // Before converting to an int type, check
        // to ensure that file is not larger than Integer.MAX_VALUE.
        if (length > Integer.MAX_VALUE) {
            // File is too large
            System.out.println("File Length :=" + length + " Integer.MAX_VALUE :=" + Integer.MAX_VALUE);
        }

        // Create the byte array to hold the data
        byte[] bytes = new byte[(int) length];

        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
            offset += numRead;
        }

        // Ensure all the bytes have been read in
        if (offset < bytes.length) {
            throw new IOException("Could not completely read file " + file.getName());
        }

        // Close the input stream and return bytes
        is.close();
        return bytes;
    }

    public static void memCheck() {
        memCheck(2);
    }

    public static void memCheck(int multiplier) {
        if(multiplier  < 2){
            multiplier = 2;
        }
        long maxMemory = Runtime.getRuntime().maxMemory();
        long totalMemory = Runtime.getRuntime().totalMemory();
        long free = Runtime.getRuntime().freeMemory();
        long freeMemory = maxMemory - totalMemory + free;

        while (freeMemory < NuggetConstants.CHUNK_SIZE * multiplier) {
            System.gc();
            freeMemory = Runtime.getRuntime().maxMemory() - Runtime.getRuntime().totalMemory() + Runtime.getRuntime().freeMemory();
        }
    }
}
